A composition written and produced by me using Vocaloid GUMI ENGLISH to sing the vocals. On Youtube, it currently has over 17,000,000 views and hundreds of covers. On Nico Nico Douga, ECHO has been rapidly approaching 4,000,000 views, becoming the second overseas VOCALOID song to reach the hall of fame (100,00 views) and first overseas VOCALOID song to reach the hall of legend (1,000,000 views). ECHO has been featured on television as the 2nd most popular VOCALOID song of 2015, is singable in JoySound and DAM karaoke, playable in various rhythm games such as SOUND VOLTEX, MAIMAI, GROOVE COASTER, etc, and became popular enough for a novel adaption by PHP Comix.